Sonos ZP100

Friday 28th March, 2008
Over at, Alan Graham poses the question "How Green is your music?".

He exposes details of his own system which incorporates various components but what caught my eye was his use of the Sonos Digital Music System. I use this Sonos multi-room system myself in several areas of the house so it was on my list of gadgets to test but, as Alan doesn't have exist power consumption figures himself, I thought it was time to bump it up the list and get it tested.


I got some surprising results...

The ZP100 ZonePlayer was the first product release by Sonos back in 2003. It's a wireless music system that will playback digital music stored on your PC allowing you to play it and control it all over the house. If you've ripped all your music from CD for an mp3player but still can't hear it in the kitchen, Sonos is the solution and you won't need to drill any holes.

In standby mode, the 50W per channel amplifier is off and the unit is just listening for wireless communications from the handheld controller or other ZonePlayers you may have scattered around the house. This makes the unit as power efficient as possible.

Plugging our in-line electricity meter between Sonos and the wall outlet, we can measure it's power consumption in the different modes.

In standby mode, with just the wifi adapter listening, Sonos (running on a measured 244v/49.9Hz outlet) draws 0.04 amps, a power use of just 5watts.

I selected my favourite track of the moment on the Sonos controller and playback started immediately and the extra power draw was immediately visible. But it wasn't a lot..considerably less than you might think. Being a 50 watts per channel amplifier I was, possibly naively, expecting this unit to draw 100W or more. But no...

Music playing at a reasonable volume through the speakers I could clearly see a power consumption of just 12 watts. I hit the 'mute' button on the front of the unit and consumption immediately dropped straight back to the standby power of 5 watts...although occasionally it clicked onto 6W which showed it was slightly busier doing background tasks. I thought I'd play around with some different volume levels to see if power consumption was affected.

Starting at completely zero volume, i see a comsumption of just 5 watts. As soon as I engage one tiny bar of volume, the amplifier kicks in and jumps to 12 watts. At 25% volume...12watts. At 50% volume...12watts. At 75% volume...12 watts. But a couple of bars after 75%, the power consumption levels escalated did the pain in my ears! By the time we reached 100% volume we're using some 48 watts of electricity at peak, although it fluctuated wildly around the 40-50watts range. It seems that whilst power consumption was rock solid all the way up the power range, at the top end it really got a bit wild. But so did the sound...

I noticed that at max volume I was getting a lot of distortion and it just sounded terrible. I know Sonos has a good quality amplifier so I wondered why for a few moments and then realised I was playing back a very low bitrate (poor quality) 128kbps mp3 file. Could this poor quality file really be causing the erratic power consumption?

95% of my collection, over 12,000 songs approaching 300GB, is ripped in the Apple Lossless codec. This gives some compression whilst completely retaining the exact CD quality, it's in the options in iTunes if you're interested. So I queued up another song or two that I knew I had ripped in the lossless codec. To my absolute amazement, it made a difference.

Zero volume - 5 Watts. 25% - 12 Watts. 50%, -12 Watts. 75%  - 12 Watts. And then we broke the 75% barrier...and almost nothing happened. At maximum volume, with crystal clear stereo sound and zero distortion, we pulling just 19 Watts...PEAK. The power consumption actually, wavered around the 15-20 Watts range, but never actually hit 20 Watts.

So at higher volume levels, we're talking less than HALF the power consumption when using high quality source files instead of mp3.

Go Green...Go Lossless!

Edit: OK, this may not be entirely true...that the codec affects consumption. Read the comments below for more info!

Shortly I'll be measuring power consumption of the other Sonos components, the ZP80 ZonePlayer and the CR100 controller, the results will be right here on

  1. 1) Amit Said: (03/05/2014 18:16:27 GMT) Gravatar Image
    Idle power consumption matrix

    Sonos has documented the idle power consumption of their players at

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